Amino-terminated poly(aryl ether ketones)

ABSTRACT

Described herein are novel amino-terminated poly(aryl ether ketone) oligomers and methods for their production. These amino-terminated poly(aryl ether ketone) oligomers are used as building blocks for a variety of polymers and copolymers.

This is a continuation of application Ser. No. 526,386, filed May 21,1990 now abandoned which in turn is a divisional of Ser. No. 06/889,203,filed Jul. 25, 1986 now U.S. Pat. No. 4,959,424.

FIELD OF THE INVENTION

This invention is directed to novel amino-terminated poly(aryl etherketone) oligomers. Processes for the preparation of the subjectoligomers are also described. The novel diamino-poly(aryl ether ketones)are useful building blocks for a variety of polymers and copolymers.

BACKGROUND OF THE INVENTION

Poly(aryl ether ketone)s are a known class of engineering polymers.Several poly(aryl ether ketone)s are highly crystalline with meltingpoints above 300° C. Two of these crystalline poly(aryl ether ketone)sare commercially available and are of the following structure: ##STR1##

Over the years, there has been developed a substantial body of patentand other literature directed to the formation and properties ofpoly(aryl ethers) (hereinafter called "PAE"). Some of the earliest worksuch as by Bonner, U.S. Pat. No. 3,065,205, involves the electrophilicaromatic substitution (viz. Friedel-Crafts catalyzed) reaction ofaromatic diacylhalides with unsubstituted aromatic compounds such asdiphenyl ether. The evolution of this class to a much broader range ofPAEs was achieved by Johnson et al., Journal of Polymer Science, A-1,vol. 5, 1967, pp. 2415-2427, Johnson et al., U.S. Pat. Nos. 4,108,837,and 4,175,175. Johnson et al. show that a very broad range of PAEs canbe formed by the nucleophilic aromatic substitution (condensation)reaction of an activated aromatic dihalide and an aromatic diol. By thismethod, Johnson et al. created a host of new PAEs including a broadclass of poly(aryl ether ketones), hereinafter called "PAEK's".

In recent years, there has developed a growing interest in PAEK's asevidenced by Dahl, U.S. Pat. No. 3,953,400; Dahl et al., U.S. Pat. No.3,956,240; Dahl, U.S. Pat. No. 4,247,682; Rose et al., U.S. Pat. No.4,320,224; Maresca, U.S. Pat. No. 4,339,568; Attwood et al., Polymer,1981, vol 22, August, pp. 1096-1103; Blundell et al., Polymer, 1983,vol. 24, August, pp. 953-958, Attwood et al., Polymer Preprints, 20, No.1, April 1979, pp. 191-194; and Rueda et al., Polymer Communications,1983, vol. 24, September, pp. 258-260. In early to mid-1970, RaychemCorp. commercially introduced a PAEK called STILAN™, a polymer whoseacronym is PEK, each ether and keto group being separated by1,4-phenylene units. In 1978, Imperial Chemical Industries PLC (ICI)commercialized a PAEK under the trademark Victrex PEEK. As PAEK is theacronym of poly(aryl ether ketone), PEEK is the acronym of poly(etherether ketone) in which the phenylene units in the structure are assumed.

Thus, PAEK's are well known; they can be synthesized from a variety ofstarting materials; and they can be made with different meltingtemperatures and molecular weights. The PAEK's are crystalline, and asshown by the Dahl and Dahl et al. patents, supra, at sufficiently highmolecular weights they can be tough, i.e., they exhibit high values (>50ft-lbs/in²) in the tensile impact test (ASTM D-1822). They havepotential for a wide variety of uses, but because of the significantcost to manufacture them, they are expensive polymers. Their favorableproperties class them in the upper bracket of engineering polymers.

PAEK's may be produced by the Friedel-Crafts catalyzed reaction ofaromatic diacylhalides with unsubstituted aromatic compounds such asdiphenyl ether as described in, for example, U.S. Pat. No. 3,065,205.These processes are generally inexpensive processes; however, thepolymers produced by these processes have been stated by Dahl et al.,supra, to be brittle and thermally unstable. The Dahl patents, supra,allegedly depict more expensive processes for making superior PAEK's byFriedel-Crafts catalysis. In contrast, PAEK's such as PEEK made bynucleophilic aromatic substitution reactions are produced from expensivestarting fluoro monomers, and thus would be classed as expensivepolymers.

These poly(aryl ether ketone)s exhibit an excellent combination ofproperties; i.e., thermal and hydrolytic stability, high strength andtoughness, wear and abrasion resistance and solvent resistance. Thus,articles molded from poly(aryl ether ketones) have utility where highperformance is required. However, in some applications where articleshaving a complex shape are sought fabrication difficulties arise due tothe high melt viscosity of the poly(aryl ether ketones).

It is, therefore, often of interest to modify the poly(aryl etherketones) in a manner such that their excellent properties be retained,but their high melt viscosity reduced to more practical levels. Also, insome applications such as when the poly(aryl ether ketone) is to be usedas a thermoplastic composite matrix resin, its glass transitiontemperature (Tg) may not be as high as desired for the particularapplication. This is due to the fact that polymers, even crystallinepolymers, exhibit excessive loss of modulus, strength and creepresistance above their Tg's. This loss in properties may not beacceptable in cases where the materials are to be used as thermoplasticcomposite matrix resins. Once again, proper modification of thepoly(aryl ether ketone) backbone may become imperative.

THE INVENTION

The present invention is directed to novel diamino-terminated poly(arylether ketone) oligomers. Processes for the preparation of the subjectmaterials are also described. The amino functions that are present atboth ends of the oligomer chain allow for the incorporation of thelatter into a variety of polymers and copolymers wherein the excellentcharacteristics of the poly(aryl ether ketone) are maintained, andwherein its undesirable features are obviated. Examples of suchsuccessful modification are the novel polyetherimide polymers, asdescribed in U.S. Pat. No. 4,540,748.

The crystalline poly(aryl ether ketone) oligomers which are suitable foruse herein can be generically characterized as containing repeatingunits of one or more of the following formulae: ##STR2## wherein Ar isindependently a divalent aromatic radical selected from phenylene,biphenylene or naphthylene, X is independently O, ##STR3## or a directbond and n is an integer of from 0 to 3, b, c, d and e are 0 to 1 and ais an integer of 1 to 4 and preferably d is 0 when b is 1.

Preferred poly(aryl ketone)s include those having a repeating unit ofthe formula: ##STR4##

The diamino-poly(aryl ketone) oligomers are prepared from thecorresponding dihydroxy- or dihalo-terminated products. The latter aremade using methods known in the art. One such method comprises heatingat least one bisphenol with at least one dihalobenzenoid compound in thepresence of a base. The use of an excess of one of the reagents, i.e.,of the bisphenol or of the dihalobenzenoid compound, leads tofunctionally terminated oligomers having either dihydroxy- ordihalo-termination, respectively. The molecular weight of the oligomersis a function of the excess utilized. The higher the excess of one ofthe reagents, the lower is the molecular weight of the resultingoligomer.

In another embodiment, the dihydroxy-terminated oligomers may beobtained by hydrolysis of the corresponding dihalo-terminated materials.Conversely, the dihydroxy-end-capped products may be reacted in thepresence of base with a molar excess of the dihalobenzenoid compound toyield the dihalo-terminated oligomer.

In still another embodiment, a halophenol may be reacted with itselfand, after reaching the desired molecular weight, reacted with a slightamount of either a bisphenol or a dihalobenzenoid compound to give therespective dihydroxy end-capped or dihalo end-capped oligomers.

Preferred bisphenols in such a process include:

hydroquinone,

4,4'-dihydroxybenzophenone,

4,4'-dihydroxybiphenyl, and

4,4'-dihydroxydiphenyl ether.

Preferred dihalo and halophenol compounds include:

4-(4'-chlorobenzoyl)phenol,

4-(4'-fluorobenzoyl)phenol,

4,4'-difluorobenzophenone,

4,4'-dichlorobenzophenone,

4-chloro-4'-fluorobenzophenone, ##STR5##

The poly(aryl ketone) oligomers may be produced by the process asdescribed in, for example, U.S. Pat. No. 4,176,222. This processcomprises heating in the temperature range of 100° to 400° C., (i) anexcess of at least one bisphenol and at least one dihalobenzenoidcompound, or (ii) an excess of at least one dihalobenzenoid compound andat least one bisphenol, and/or (iii) at least one halophenol followed byreaction with a small amount of a diphenol or of a dihalobenzenoidcompound in order to ensure hydroxyl or halo termination in which in thedihalobenzenoid compound or halophenol, the halogen atoms are activatedby --CO-- groups ortho or para thereto, with a mixture of sodiumcarbonate or bicarbonate and a second alkali metal carbonate orbicarbonate, the alkali metal of said second alkali metal carbonate orbicarbonate having a higher atomic number than that of sodium, theamount of said second alkali metal carbonate or bicarbonate being suchthat there are 0.001 to 0.2 gram atoms of said alkali metal of higheratomic number per gram atom of sodium, the total amount of alkali metalcarbonate or bicarbonate being such that there is at least one alkalimetal atom for each phenol group present, and thereafter separating theoligomer from the alkali metal halide.

The higher alkali metal carbonates or bicarbonates are thus selectedfrom the group consisting of potassium, rubidium and cesium carbonatesand bicarbonates. Preferred combinations are sodium carbonate orbicarbonate with potassium carbonate or cesium carbonate.

The alkali metal carbonates or bicarbonates should be anhydrousalthough, if hydrated salts are employed, where the polymerizationtemperature is relatively low, e.g., 100° to 250° C., the water shouldbe removed, e.g., by heating under reduced pressure, prior to reachingthe polymerization temperatures.

Where high polymerization temperatures (>250° C.) are used, it is notnecessary to dehydrate the carbonate or bicarbonate first as any wateris driven off rapidly before it can adversely affect the course of thepolymerization reaction. Optionally, an entraining organic medium suchas toluene, xylene, chlorobenzene and the like, can be used to removewater from the reaction mixture.

The total amount of alkali metal carbonate or bicarbonate employedshould be such that there is at least 1 atom of alkali metal for eachphenol group. Hence, there should be at least 1 mole of carbonate, or 2moles of bicarbonate, per mole of the aromatic diol.

An excess of carbonate or bicarbonate may be employed. Hence there maybe 1 to 1.2 atoms of alkali metal per phenol group. While the use of anexcess of carbonate or bicarbonate may give rise to faster reactions,there is the attendant risk of cleavage of the resulting polymer,particularly when using high temperatures and/or the more activecarbonates.

As stated above the amount of the second (higher) alkali metal carbonateor bicarbonate employed is such that there are 0.001 to about 0.2 gramatoms of the alkali metal of higher atomic number per gram atom ofsodium.

Thus when using a mixture of carbonates, e.g., sodium carbonate andcesium carbonate, there should be 0.1 to about 20 moles of cesiumcarbonate per 100 moles of sodium carbonate. Likewise when using amixture of a bicarbonate and a carbonate, e.g., sodium bicarbonate andpotassium carbonate, there should be 0.05 to 10 moles of potassiumcarbonate per 100 moles of sodium bicarbonate.

A mixed carbonate, for example sodium and potassium carbonate, may beemployed as the second alkali metal carbonate. In this case, where oneof the alkali metal atoms of the mixed carbonate is sodium, the amountof sodium in the mixed carbonate should be added to that in the sodiumcarbonate when determining the amount of the mixed carbonate to beemployed.

Preferably, from 0.005 to 0.1 gram atoms of the alkali metal of thesecond alkali metal carbonate or bicarbonate per gram atom of sodium isused.

The reaction is carried out in bulk or in the presence of an inertsolvent.

Preferably the solvent employed is an aliphatic or aromatic sulfoxide orsulfone of the formula

    R--S(O).sub.x --R'

where x is 1 or 2 and R and R' are alkyl or aryl groups and may be thesame or different. R and R' may together form a divalent radical.Preferred solvents include dimethyl sulfoxide, dimethyl sulfone,sulfolane (1,1-dioxothiolan), or aromatic sulfones of the formula:##STR6## where R₂ is a direct link, an oxygen atom or two hydrogen atoms(one attached to each benzene ring) and R₃ and R'₃, which may be thesame or different, are hydrogen atoms and alkyl or phenyl groups.Examples of such aromatic sulfones include diphenylsulfone,dibenzothiophen dioxide, phenoxathiin dioxide and 4-phenylsulfonylbiphenyl. Diphenylsulfone is the preferred solvent.

The polymerization temperature is in the range of from about 100° toabout 400° C. and will depend on the nature of the reactants and thesolvent, if any, employed. The preferred temperature is above 270° C.The reactions are generally performed under atmospheric pressure.However, higher or lower pressures may be used.

For the production of some oligomers, it may be desirable to commencepolymerization at one temperature, e.g., between 200° and 250° C. and toincrease the temperature as polymerization ensues. This is particularlynecessary when making oligomers having only a low solubility in thesolvent. Thus, it is desirable to increase the temperature progressivelyto maintain the oligomer in solution as its molecular weight increases.

To minimize cleavage reactions it is preferred that the maximumpolymerization temperature be below 350° C.

This invention is also directed to an improved process for making theoligomers in comparatively shorter reaction times overall than by usingpotassium fluoride alone or by using a combination of sodium carbonateor bicarbonate and a second higher alkali metal carbonate orbicarbonate.

Specifically, this process is directed to preparing the poly(aryl etherketone) precursors by the reaction of a mixture of an excess of thediphenol and of the aromatic activated dihalo compound or, conversely,of an excess of the aromatic activated dihalo compound and of thediphenol, and/or of the activated halophenol followed by reaction with asmall amount of a diphenol or of a dihalobenzenoid compound in order toensure dihydroxy or dihalo termination, in which in the dihalobenzenoidcompound or halophenol, the halogen atoms are activated by --CO-- groupsortho or para thereto in the presence of a combination of sodiumcarbonate and/or bicarbonate and an alkali metal halide selected frompotassium, rubidium, or cesium fluoride or chloride, or combinationsthereof.

The reaction is carried out by heating a mixture of the reactants asdescribed herein, at a temperature of from about 100° to about 400° C.The reaction is conducted in the presence of added sodium carbonateand/or bicarbonate and potassium, rubidium or cesium fluorides orchlorides. The sodium carbonate or bicarbonate and the chloride andfluoride salts should be anhydrous although, if hydrated salts areemployed, where the reaction temperature is relatively low, e.g., 100°to 250° C., the water should be removed, e.g., by heating under reducedpressure, prior to reaching the reaction temperature.

Where high reaction temperatures (>250° C.) are used, it is notnecessary to dehydrate the carbonate, bicarbonate, the chloride orfluoride salts first as any water is driven off rapidly before it canadversely affect the course of the reaction. Optionally, an entrainingorganic medium can be used to remove water from the reaction such astoluene, xylene, chlorobenzene, and the like.

The total amount of sodium carbonate or bicarbonate and potassium,rubidium or cesium fluoride or chloride, or combinations thereofemployed should be such that there is at least 1 atom of total alkalimetal for each phenol group, regardless of the anion (carbonate,bicarbonate or halide).

Preferably, from about 1 to about 1.2 atoms of the total alkali metalfor each phenol group is used. In another preferred embodiment fromabout 0.001 to about 0.5 atoms of alkali metal (derived from a higheralkali metal halide) is used for each phenol group.

The sodium carbonate or bicarbonate and the potassium, rubidium orcesium fluoride are used such that the ratio of potassium, rubidium orcesium to sodium therein is from about 0.001 to about 0.5, preferablyfrom about 0.01 to about 0.25, and most preferably from about 0.02 toabout 0.20.

An excess of total alkali metal may be employed. Hence there may beabout 1 to about 1.7 atoms of alkali metal per phenol group. While theuse of a large excess of alkali metal may give rise to faster reactions,there is the attendant risk of cleavage of the resulting polymer,particularly when using high temperatures and/or the more active alkalimetal salts. Of course it is well known to those skilled in the art thatcesium is a more active metal and potassium is a less active metal sothat less cesium and more potassium are used. Further, the chloridesalts are less active than the fluoride salts so that more chloride andless fluoride is used.

The reactions are carried out in bulk or in the presence of an inertsolvent.

Preferably the solvent employed is an aliphatic or aromatic sulfoxide orsulfone of the formula

    R--S(O).sub.x --R'

where x is 1 or 2 and R and R' are alkyl or aryl groups and may be thesame or different. R and R' may together form a divalent radical.Preferred solvents include dimethyl sulfoxide, dimethyl sulfone,sulfolane (1,1-dioxothiolan), or aromatic sulfones of the formula:##STR7## where R₂ is a direct link, an oxygen atom or two hydrogen atoms(one attached to each benzene ring) and R₃ and R'₃, which may be thesame or different, are hydrogen atoms and alkyl or phenyl groups.Examples of such aromatic sulfones include diphenylsulfone,dibenzothiophen dioxide, phenoxathiin dioxide and 4-phenylsulfonylbiphenyl. Diphenylsulfone is the preferred solvent.

The reaction temperature is in the range of from about 100° to about400° C. and will depend on the nature of the reactants and the solvent.The preferred temperature is above 250° C. The reactions are preferablycarried out at ambient pressure. However, higher or lower pressures canalso be used. The reaction is generally carried out in an inertatmosphere.

For the production of some oligomers it may be desirable to commencereaction at one temperature, e.g., between 200° and 250° C. and toincrease the temperature as reaction ensues. This is particularlynecessary when making higher molecular weight oligomers having only alow solubility in the solvent. Thus, there it is desirable to increasethe temperature progressively to maintain the oligomer in solution asits molecular weight increases.

To minimize cleavage reactions it is preferred that the maximumpolymerization temperature be below 350° C.

Also, poly(aryl ketone) oligomers such as those containing repeatingunits of the formula: ##STR8## may be produced by Friedel-Craftsreactions utilizing hydrogen fluoride-boron trifluoride catalysts asdescribed, for example, in U.S. Pat. No. 3,953,400.

Additionally, poly(aryl ketone) oligomers of the following formula:##STR9## may be prepared by Friedel-Crafts reactions using a boronfluoride-hydrogen fluoride catalyst as described in, for example, U.S.Pat. Nos. 3,441,538; 3,442,857 and 3,516,966.

Additionally, the oligomers may be prepared by Friedel-Crafts processesas described in, for example, U.S. Pat. Nos. 3,065,205; 3,419,462;3,441,538; 3,442,857; 3,516,966; and 3,666,612. In these patents a PAEKis produced by Friedel-Crafts polymerization techniques usingFriedel-Crafts catalysts such as aluminum trichloride, zinc chloride,ferric bromide, antimony pentachloride, titanium tetrachloride, etc. anda solvent.

The preferred Friedel-Crafts catalysts are aluminum chloride, antimonypentachloride and ferric chloride. Other Friedel-Crafts catalysts, suchas aluminum bromide, boron trifluoride, zinc chloride, antimonytrichloride, ferric bromide, titanium tetrachloride, and stanicchloride, can also be used. In the preferred embodiment, an excess of upto 100 mole percent of the acid catalyst is used.

The polymerization is generally carried out in the presence of asolvent. The preferred organic solvent is 1,2-dichloroethane. Othersolvents such as symmetrical tetrachloroethane, o-dichlorobenzenehydrogen fluoride, methylene chloride, trichloromethane,trichloroethylene, or carbon disulfide may be employed. Cosolvents suchas nitromethane, nitropropane, dimethyl formamide, sulfolane, etc. maybe used. Concentrations as low as 3 to as high as 40 weight percent maybe used. Generally lower concentrations are preferred when highermolecular weight oligomers are being prepared. Higher concentrations arepreferably used when low molecular weight oligomers are prepared.

The reaction may be carried out over a range of temperatures which arefrom about -40° C. to about 160° C. In general, it is preferred to carryout the reaction at a temperature in the range of 0° to 30° C. In somecases it is advantageous to carry out the reaction at temperatures above30° C. or below 0° C. Most preferably, the reactions are carried out attemperatures below 0° C. The reaction may be carried out at atmosphericpressure although higher or lower pressures may be used. Reaction timesvary depending on the reactants, etc. Generally, reaction times of up to6 hours and longer are preferred.

The polyketone oligomers may also be prepared according to the processas described in, for example, U.S. Defensive Publication T 103,703 andU.S. Pat. No. 4,396,755. In such processes, reactants such as (a) anaromatic monocarboxylic acid, (b) a mixture of at least one aromaticdicarboxylic acid, and an aromatic hydrocarbon, and (c) combinations of(a) and (b) are reacted in the presence of a fluoroalkane sulphonicacid, particularly trifluoromethane sulphonic acid.

Additionally, poly(aryl ether ketone) oligomers of the followingformulas: ##STR10## may also be prepared according to the process asdescribed in, for example, U.S. Pat. No. 4,398,020. In such a process,

(a) a mixture of

(i) at least one aromatic diacyl halide of the formula:

    YOC--Ar.sub.1 --COY

where --Ar₁ -- is a divalent aromatic radical, Y is halogen and COY isan aromatically bound acyl halide group, which diacyl halide ispolymerizable with at least one aromatic compound of (a)(ii), and

(ii) at least one aromatic compound of the formula:

    H--Ar.sub.2 --H

wherein --Ar₂ -- is a divalent aromatic radical and H is an aromaticallybound hydrogen atom, which compound is polymerizable with at least onediacyl halide of (a)(i), or

(b) at least one aromatic monoacyl halide of the formula:

    H--Ar.sub.3 --COW

where --Ar₃ -- is a divalent aromatic radical and H is an aromaticallybound hydrogen atom, W is halogen, and COW is an aromatically bound acylhalide group, which monoacyl halide is self-polymerizable, or

(c) a combination of (a) and (b) is reacted in the presence of afluoroalkane sulphonic acid.

In order to obtain oligomers having the desired dihydroxyl or dihalotermination, appropriate capping agents must be used in theFriedel-Crafts catalyzed reactions described above. This can beaccomplished as shown.

VARIANT 1

In this variant, a diacid dihalide, is polycondensed with a hydrocarbonreactant. An excess of the dihalide is used; reaction of the acidhalide-terminated ##STR11## intermediate (5) with a halohydrocarbon (6)yields the dihalo-terminated oligomer (7). Hydrolysis of the latteryields the desired dihydroxy poly(aryl ether ketone) oligomer (8).##STR12##

In the above equations Y, Ar₁ and Ar₂ are as defined above. The groupAr₄ is a divalent aromatic radical, preferably paraphenylene; X ishalogen, preferably chlorine or fluorine. Other preferredhalohydrocarbons (6) are those represented by the formulae (9)-(11).##STR13##

VARIANT 2

In this variant an excess of hydrocarbon is condensed with the diacidshalide. The intermediate (12) is then reacted with a halo-substitutedmonoacid halide (13) to give the halo-terminated oligomer (14).Hydrolysis of the latter leads to the dihydroxy- ##STR14## terminatedpoly(aryl ether ketone) oligomer (15).

In the above equations X, Y, Ar₁ and Ar₂ are as defined above; Ar₅ is adivalent aromatic radical, preferably p-phenylene. Other preferredX--Ar₅ COY are for example (16) and (17). ##STR15##

VARIANT 3

In this variant an aromatic monoacyl halide is polymerized in thepresence of a Friedel-Crafts catalyst to the oligomer stage (19). Theoligomer (19) is then end-capped ##STR16## by both XAr₄ H and XAr₅ COYas shown: ##STR17## Hydrolysis of (20) yields the dihydroxy-terminatedpoly(aryl ether ketone) oligomer (21). ##STR18##

In the above equations Ar₃, Ar₄, Ar₅, X, and Y are as defined above.

For all three variants the value of n should be such that the numberaverage molecular weight of the oligomer be at least 500, preferably atleast 1,000, and most preferably at least 1,200.

Specifically, the precursor oligomers may be prepared by reacting any ofthe well-known aromatic coreactants such as diphenyl sulfide,dibenzofuran, thianthrene, phenoxathiin, dibenzodioxine, phenodioxin,diphenylene, 4,4'-diphenoxybiphenyl, xanthone, 2,2'-diphenoxybiphenyl,1,4-diphenoxybenzene, 1,3-diphenoxybenzene, 1-phenoxynapthalene,1,2-diphenoxynapthalene, diphenoxybenzophenone, diphenoxy dibenzoylbenzene, diphenyl ether, 1,5-diphenoxynapthalene, and the like. Amongthese, diphenyl ether, diphenyl, diphenyl methane, 1,4-diphenoxybenzene, and 4,4'-diphenoxy diphenyl ether are preferred.

Similarly, the following compounds are diacyl halides which may be usedas reactants: terephthaloyl chloride, isophthaloyl chloride,thio-bis(4,4'-benzoyl chloride), benzophenone-4,4'-di(carbonylchloride), oxy-bis(3,3'-benzoyl chloride), diphenyl-3'di(carbonylchloride), carbonyl-bis(3,3'-benzoyl chloride),sulfonyl-bis(4,4'-benzoyl chloride), sulfonyl-bis(3,3'-benzoylchloride), sulfonyl-bis(3,4'-benzoyl chloride), thio-bis(3,4'-benzoylchloride), diphenyl-3,4'-di(carbonyl chloride),oxy-bis[4,4'-(2-chlorobenzoyl chloride)], napthalene-1,6-di(carbonylchloride), napthalene-2,5-di(carbonyl chloride),napthalene-2,6-di(carbonyl chloride),oxy-bis[7,7'-napthalene-2,2'-di(carbonyl chloride)],thio-bis[8,8'-napthalene-1,1-di(carbonyl chloride)],[7,7'-binaphthyl-2,2-di(carbonyl chloride)], diphenyl-4,4'-di(carbonylchloride), carbonyl-bis[7,7'-napthalene-2,2'-di(carbonyl chloride)],sulfonyl-bis[6,6'-napthalene-2,2'-di(carbonyl chloride)],dibenzofuran-2,7-di(carbonyl chloride) and the like.

Illustrative of suitable acyldihalides include carbonyl chloride(phosgene), carbonyl bromide, carbonyl fluoride and oxalyol chloride.

Preferably, diphenyl ether and/or diphenoxybenzene are reacted withterephthaloyl chloride and/or phosgene.

As mentioned before, the dihydroxy or dihalo end-capped poly(aryl etherketone) blocks have number average molecular weights of at least 500,preferably of at least 1,000, and most preferably of at least 1,200.

The diamino-terminated oligomers are prepared from the correspondingdihydroxy- or dihalo-end-capped materials via the methods describedbelow.

METHOD I

A dihalo-terminated poly(aryl ether ketone) is reacted with anaminophenol in the presence of base. The reaction is exemplified usingoligomer (14) (equation VII)). ##STR19## In the equation above Ar₁, Ar₂,and Ar₅ are as defined above; X is as defined above and is preferablyfluorine; Ar₆ is a divalent aromatic radical such as p-phenylene,m-phenylene, 4,4'-biphenylene, naphthylene, and the like.

The reaction depicted in equation (VII) can be performed in bulk or insolution. It is preferably conducted in an aprotic solvent. Theconditions, i.e., base, solvents, etc., are the same as those describedfor the nucleophilic preparation of the starting dihalo-terminatedoligomers. The systems sodium carbonate/potassium carbonate or sodiumcarbonate/potassium fluoride are used preferably as the base. Diarylsulfones, in particular diphenyl sulfone, are the preferred reactionsolvents. The preferred temperature range is from about 250° C. to about350° C., although lower and higher temperatures may also be used. Thereactions are preferably run under an inert atmosphere; they aregenerally conducted under atmospheric pressure; higher and lowerpressures can also be applied. In order to ensure proper diaminotermination, it is imperative that at least two moles of the aminophenolbe employed per mole of the starting dihalo end-capped oligomer. It ispreferred, however, to use more than 2 moles of the aminophenolend-capping reagent. Thus, for best results, at least 2.5 moles of theaminophenol and, in some instances, amounts as high as 4 or 5 moles ofthe aminophenol, should be used per mole of the dihalo oligomer.

The end-capping reaction can be performed in a separate step, i.e.,using isolated and purified dihalo-terminated starting material.Alternatively, the end-capping step may be conducted in the same vesselin which the starting material has been prepared by simply adding theaminophenol terminator (and possibly solvent and/or base) to thereaction mixture at the appropriate moment. This variant is particularlyuseful when the starting dihalo end-capped oligomer is also prepared bythe nucleophilic condensation reaction. In still another embodiment, allof the reagents, i.e., the diphenol, the excess of the dihalo benzenoidcompound, and the aminophenol are charged into the vessel andpolycondensed nucleophilically to the desired diamino-terminatedpoly(aryl ether ketone).

As mentioned above, the group Ar₆ is a divalent C₁ to C₂₀ aromaticradical optionally substituted with an inert group, i.e., a C₁ to C₇alkyl group, a C₅ to C₁₂ cycloalkyl group, or a halogen. Preferredamino-phenols are shown (structures (24)-(28)). ##STR20##

METHOD II

This method involves a condensation step of the dihydroxy-terminatedoligomer with a halo-nitroaromatic compound, followed by the reductionof the nitro function to the corresponding amino function. The sequenceis illustrated in equation (VIII) using oligomer (8). ##STR21## In theequation above Ar₁, Ar₂, Ar₄, and X are as defined above; the group Ar₇is a divalent aromatic radical such as p-phenylene; X and NO₂ are in apara- or ortho-configuration. The group Ar₇ may carry additionalsubstituents such as additional halo functions and/or additional nitrofunctions. In this latter case, reduction will lead to tetraamino, orgenerally polyamino, terminated poly(aryl ether ketones). The group Ar₇may also carry alkyl (C₁ to C₇) and cycloalkyl (C₅ to C₁₂) substituents.This is less desirable, however, due to the deactivating effect of thesegroups on the nucleophilic termination reaction.

The reaction depicted in the first step of equation (VIII) can beperformed in bulk or in solution. It is preferably conducted insolution, using an aprotic solvent. The conditions, i.e., base,solvents, etc., are the same as those described for the nucleophilicpreparation of the starting dihydroxy-terminated oligomers. The systemssodium carbonate/potassium carbonate or sodium carbonate/potassiumfluoride are the preferred bases. Diaryl sulfones, in particulardiphenyl sulfone, are the preferred reaction solvents. The preferredtemperature range is from about 250° C. to about 350° C., although lowerand higher temperatures may also be used. The reactions are preferablyrun under an inert atmosphere; they are generally conducted underatmospheric pressure; higher and lower pressures can also be applied. Inorder to ensure proper dinitro or polynitro termination, it isimperative that at least two moles of the halo-nitrobenzenoid compoundbe employed per mole of the starting dihydroxy end-capped oligomer. Itis preferred, however, to use more than 2 moles of thehalo-nitrobenzenoid end-capping reagent. Thus, for best results, atleast 2.5 moles of the halo-nitrobenzenoid compound and, in someinstances, amounts as high as 4 or 5 moles of the halo-nitrobenzenoidcompound, should be used per mole of the dihydroxy oligomer.

The end-capping reaction can be performed in a separate step, i.e.,using isolated and purified dihydroxy-terminated starting material; orit may be conducted in one step with the preparation of the oligomer.This approach is useful when the oligomer is also prepared by thenucleophilic polycondensation route. The halo-nitro compound may beadded to the reaction mixture with all of the ingredients at the startof the oligomer formation. Alternatively, the oligomer may be formedfirst and, at the appropriate moment, the halo-nitro compound added toaffect nitro end-capping. The preferred halo-nitrobenzenoid compound is(32) ##STR22##

The second step of equation (VIII) consists in reducing the nitrocompound to the corresponding diamino or polyamino poly (aryl etherketone). The preferred method of reduction is catalytic, althoughreductions by other means, e.g., by zinc powder in acid solution,stannous chloride in acid solution, hydrazine, sodium borohydride-sulfurin tetrahydrofuran as described in the Canadian Journal of Chemistry,Vol. 49, p. 2990 (1971), etc., may also be useful. The catalyticreductions use preferably palladium (e.g., Pd--C or Pd--BaSO₄),platinum, or nickel (e.g., Raney nickel) based catalysts as described inHouben-Weyl, Methoden der Organischen Chemie, Volume 11, part I, p. 360and following, 4th Edition, Georg Thieme Verlag, Stuttgart, 1957. Thereactions are performed in solution or in suspension. The preferredhydrogenation solvents are pyridine, dimethylformamide,N-methylpyrolidone, dimethyl acetamide, and diphenyl sulfone, thoughcare must be taken with the latter to avoid sulfur-aromatic ringcleavage. The temperature range for the hydrogenation varies, dependingon the particular case, from as low as room temperature, to as high as90° to 100° C., or even higher. In order to avoid formation of secondaryproducts, hydrogen pressures higher than atmospheric are preferred (1.5to 50 atmospheres, or higher, if necessary).

As mentioned before, the reactions should be performed either insolution or in suspension.

METHOD III

A third approach whereby the diamino-terminated poly(aryl ether ketones)can be prepared comprises reacting the dihalo-terminated oligomers, e.g.(7), (14), or (20) with ammonia. The reaction is illustrated in equation(IX) using the oligomer (20). ##STR23##

The reaction shown in equation (IX) can be performed either insuspension or in solution. Thus, a finely divided dihalo-terminatedpoly(aryl ketone) oligomer can be reacted in a suspension of aqueousammonia at elevated temperatures and pressures. In another embodiment,the dihalo-oligomer is reacted with ammonia in solution; preferredsolvents are the dipolar aprotic solvents such as an aromatic oraliphatic sulfoxide or sulfone of the formula:

    R--S(O).sub.x R.sup.1

where x is 1 or 2 and R and R¹ are alkyl or aryl groups and may be thesame or different. R and R¹ may together form a divalent radical.Preferred solvents include dimethyl sulfoxide, dimethyl sulfone,sulfolane (1,1-dioxothiolan), or aromatic sulfones of the formula:##STR24## where R₂ is a direct link, an oxygen atom or two hydrogenatoms (one attached to each benzene ring) and R₃ and R'₃, which may bethe same or different, are hydrogen atoms and alkyl or phenyl groups.Examples of such aromatic sulfones include diphenyl sulfone,dibenzothiophene dioxide, phenoxathiin dioxide and 4-phenylsulfonylbiphenyl. Diphenyl sulfone is the preferred solvent.

The solution reaction is also performed at high temperatures andpressures. The reaction temperatures both in the suspension and solutionvariants are in the range of from about 200° to 350° C., the range offrom about 250° to 320° C. being preferred.

The reaction shown in equation (IX) can be performed using aminesinstead of ammonia. Methylamine and phenylamine are of particularinterest. A variety of other primary and secondary amines are alsouseful.

The amination reaction of equation (IX) can be catalyzed with copper.sup.(1) salts. Cuprous chloride is preferred. Preferred amounts are inthe range of from 0.01 to 5 wt. % of the cuprous salt based on thepoly(aryl ketone) oligomers used. After completion of the reaction thecatalyst should be removed in order that the thermal stability of thediamino-derivative not be adversely affected. Removal is preferablyperformed using appropriate chelating agents such as, for example,citric acid.

A certain proportion of keto groups of the starting dihalo-terminatedoligomer will react with ammonia to form the corresponding ketiminederivatives. Thus, more than 4 moles of ammonia per mole of oligomershould be used in the amination. Amounts as high as 15 to 20 moles (oreven higher) of ammonia per mole of the dihalo-terminated oligomer mayhave to be used depending on the particular oligomer employed. Theketimine groups are easily converted back to the keto groups viahydrolysis.

The preferred routes to the novel diamines of the instant invention aremethods I and III. Method I is the most preferred.

The novel diamino poly(aryl ether ketones) are useful building blocksfor a variety of polymers and copolymers. Their usefulness inpolyetherimides was recently described in U.S. Pat. No. 4,540,748.

EXAMPLES

The following examples serve to give specific illustrations of thepractice of this invention, but they are not intended in any way tolimit the scope of this invention.

PREPARATION OF OLIGOMERS EXAMPLE 1

A 2000 ml flask was fitted with a mechanical stirrer, nitrogen spargetube, thermometer, reflux condenser and gas outlet connected to anaqueous sodium hydroxide trap. The apparatus was purged with nitrogenand while under a positive pressure was charged with 1400 ml of1,2-dichloroethane, 2.03 g (0.010 moles) of isophthaloyl chloride, 38.57g (0.190 moles) of terephthaloyl chloride, 35.74 g (0.210 moles) ofdiphenylether and 3.17 g (0.020) moles of p-fluorobenzoyl chloride. Themixture was cooled to 0° C. as 12.80 g (0.546 moles) of aluminumtrichloride was added at a rate such as not to exceed 5° C. After 6hours at 0° C., the heterogeneous slurry was allowed to warm to roomtemperature (about 25° C.) and stirred for an additional 17 hours. Theexcess solvent was decanted and the precipitate was added to diluteaqueous acid (3000 ml H₂ O/100 ml conc. hydrochloric acid) and heated toreflux for 2 hours while the 1,2-dichloroethane was continuouslyremoved. The polymer was filtered and dried in a vacuum oven at 60° C.for 24 hours to give 60.2 grams of the final polymer having a generalstructure as shown in formula (36). The polymer had a reduced viscosityof 0.34 dl/g as measured in sulfuric acid at a concentration of 1 g/100ml at 25° C.

Its structure corresponds to formula (33) with n being of about 20 (mol.wt. of about 6,300). ##STR25##

EXAMPLE 2

A 1000 ml flask was fitted with a mechanical stirrer, reflux condenser,thermometer, nitrogen sparge tube, and gas outlet connected to anaqueous sodium hydroxide trap. The apparatus was purged with nitrogenand while under a positive pressure was charged with 85.11 g (0.500moles) of diphenylether, 68.01 g (0.335 moles) of terephthaloylchloride, 53.12 g (0.335 moles) of p-fluorobenzoyl chloride and 600 mlsof 1,2-dichloroethane. The mixture was cooled to 0° C. as 174.21 g (1.31moles) of aluminum trichloride was added at a rate such as not to exceed5° C. After 6 hours at 0° C. the viscous homogeneous mixture was allowedto warm to room temperature and stirring was continued for an additional17 hours. The entire mixture was then poured into dilute aqueous acid(3000 ml of H₂ O/100 ml conc. hydrochloric acid), refluxed withcontinuous removal of 1,2-dichloroethane and filtered. The precipitatewas refluxed in 5% hydrochloric acid (700 ml), filtered, washed at roomtemperature with distilled water (2 times using 500 ml) and methanol (2times using 500 ml) and dried in a vacuum oven at 100° C. for 24 hours.The final oligomeric crystalline poly(aryletherketone) had thestructural formula (37) and was characterized by ¹³ C NMR, by massspectroscopy and elemental analysis. ##STR26##

EXAMPLE 3

A 250 ml flask was fitted with a mechanical stirrer, nitrogen spargetube, thermometer, reflux condenser, and gas outlet connected to anaqueous sodium hydroxide trap. The apparatus was purged with nitrogenand while under positive pressure was charged with 96 ml of1,2-dichloroethane, 11.40 g (0.067 moles) of diphenyl ether, 20.30 g(0.100 moles) of terephthaloyl chloride and 6.44 g (0.067 moles) offluorobenzene. The mixture was cooled to 0° C. as 34.67 g (0.260 moles)of aluminum trichloride was added at such a rate as not to exceed 5° C.After 6 hours at 0° C. the heterogeneous slurry was allowed to warm toroom temperature and stirring was continued for an additional 17 hours.The entire mixture was then poured into dilute aqueous acid (300 mlwater/100 ml conc. hydrochloric acid) and refluxed for 2 hours with thecontinuous removal of 1,2-dichloroethane. The resultant precipitate wascollected via filtration, refluxed in 5 % hydrochloric acid (700 ml),filtered, washed in a blender with distilled water (2 times using 500ml) followed by methanol (2 times using 500 ml) at room temperature anddried in a vacuum oven at 100° C. for 24 hours. The final oligomericcrystalline poly(aryl ether ketone) having the structural formula (38)was characterized by ¹³ C NMR; its structure was also confirmed by massspectroscopy. ##STR27##

EXAMPLE 4

A 100 ml flask was fitted with a mechanical stirrer, reflux condenser,thermometer, nitrogen sparge, and gas outlet connected to an aqueoussodium hydroxide trap. The apparatus was purged with nitrogen and whileunder a positive pressure was charged with 17.02 g (0.100 moles) ofdiphenyl ether, 10.15 g (0.050 moles) of terephthaloyl chloride, 15.86 g(0.100 moles) of p-fluorobenzoyl chloride and 48 mls of1,2-dichloroethane. The mixture was cooled to 0° C. as 34.67 g (0.260moles) of aluminum trichloride was added at such a rate as not to exceed5° C. After 6 hours at 0° C. the viscous homogeneous mixture was allowedto warm to room temperature and stirring continued for an additional 17hours. The entire mixture was then poured into dilute aqueous acid (1300ml water/50 ml conc. hydrochloric acid), refluxed with continuousremoval of 1,2-dichloroethane, and filtered. The precipitate wasrefluxed in 5% hydrochloric acid (700 ml), filtered, washed at roomtemperature with water (2 times using 500 ml) and methanol (2 timesusing 500 ml) and dried in a vacuum oven at 100° C. for 24 hours. Thefinal oligomeric crystalline poly(aryl ether ketone) having thestructural formula (39) was characterized by ¹³ C NMR and its structureconfirmed by mass spectroscopy and elemental analysis. ##STR28##

EXAMPLE 5

Preparation of the hydroxyl-terminated oligomer (40). ##STR29##

A 250 ml 3-neck flask with slanted side arms fitted with a Claisen arm,nitrogen inlet tube, thermocouple probe, condenser, and stainless steelstirrer was charged with difluorobenzophenone (0.1104 mole, 24.09 gm),hydroquinone (0.115 mole, 12.66 gm), sodium carbonate (0.1173 moles,12.43 gm, ground and dried), anhydrous potassium fluoride (0.0293 mole,1.70 gm) and diphenyl sulfone (100 gm). The apparatus was evacuated andfilled with argon by means of a Firestone valve connected to the top ofthe condenser. A flow of high purity nitrogen was begun and theconnection to the Firestone valve was replaced with a bubbler. Thecontents of the flask were heated carefully by means of a heating mantleand temperature controller to melt the diphenyl sulfone. The reactionmixture was stirred and heated to 200° C. and held 30 minutes at thattemperature; it was then held at 250° C. for 1 hour, and finally at 270°C. for 2 hours. The reaction mixture was poured from the reaction flask,cooled, ground to a fine powder, and a sample refluxed successivelytwice with acetone, once with 2% hydrochloric acid, once with water, andwashed thoroughly with acetone. The dried (120°, vacuum oven) samplegave a reduced viscosity (1% in conc. sulfuric acid, 25° C.) of 0.53dl/gm. Based on reactant stoichiometry this oligomer had the structure(40) as depicted above.

EXAMPLE 6

A halo-terminated oligomer having structure (41) and wherein n is about20 ##STR30## is prepared in a manner similar to that described inExample 5, except that a suitable molar excess of4,4'-difluorobenzophenone is used.

EXAMPLE 7 End-capping of Oligomers--General Technique

A 250 ml flask is fitted with a mechanical stirrer, nitrogen inlet,thermocouple controller and a Dean Stark trap with a condenser. Theflask is charged with 0.1 mole of the dihalo- or thedihydroxy-terminated oligomer; also, about 0.120 moles of anhydroussodium carbonate and about 0.010 moles of anhydrous potassium carbonate,as well as about 30 to 40 ml of xylene (the azeotroping agent) and about80 to 100 gms of diphenyl sulfone (the dipolar aprotic solvent) areadded into the flask. It should be noted that the amounts of solventsused will depend on the type and molecular weight of the oligomer. About0.25 moles of the appropriate aminophenol (in the case when the dihalooligomer is being used) or of the nitro-halobenzenoid compound (in thecase when the dihydroxy-terminated oligomer is employed) are thencharged. The equipment is evacuated and filled with nitrogen threetimes.

Heat is then applied to raise the temperature to 200° C. for one hour;the temperature is then raised to 250° C. where it is held for about 15minutes, and then raised to the range of 280°-320° C. where it is heldfor 1 to 2 hours (generally about 0.5 hours at 280° C., 0.5 hours at300° C. and one hour at 320° C.).

The cooled solid mass is ground to a fine granular material which isextracted with two 300 ml portions of boiling acetone, followed by two500 ml portions of boiling water. The obtained end-capped oligomer isdried in vacuo till constant weight.

The prepared diamino poly(aryl ether ketones) are listed in Table I.

    TABLE I      Diamine-terminated Poly(aryl ether ketone) Oligomers Starting Oligomer     Structure Terminator Molecular Weight      ##STR31##      ##STR32##      about 1,000      "     ##STR33##      about 1,800      ##STR34##      ##STR35##      about 1,500      "     ##STR36##      about 1,800      ##STR37##      ##STR38##      about 5,000      "     ##STR39##      about 7,000      ##STR40##      ##STR41##      about 3,000      "     ##STR42##      about 4,500      ##STR43##      ##STR44##      about 2,000      "     ##STR45##      about 2,000      ##STR46##      ##STR47##      about 2,500      ##STR48##      ##STR49##      about 5,300

What is claimed is:
 1. A process for the preparation of adiamino-terminated poly(aryl ether ketone) which consists of repeatingunits of one or more of the following formulae: ##STR50## wherein Ar isindependently a divalent aromatic radical selected from phenylene,biphenylene or naphthalene, X is independently O, ##STR51## or a directbond and n is an integer of from 0 to 3, b, c, d, and e are 0 to 1 and ais an integer of 1 to 4; which process comprises reacting in a dipolaraprotic solvent a dihydroxy-terminated oligomer with a halo-nitroaromatic compound to form a corresponding dinitro-terminated oligomerand subsequently reducing in a hydrogenation solvent the nitro functionsof the dinitro-terminated oligomer to amino functions, wherein thereduction is conducted with the dinitro oligomer in suspension.
 2. Aprocess as defined in claim 1 wherein the halo-nitro aromatic compoundis a halo-nitro benzenoid compound having a formulae: ##STR52## where Xis a chlorine or fluorine ion.
 3. A process as defined in claim 1wherein the dipolar aprotic solvent is diphenyl sulfone.